export const description = 'In this section, we will learn how to configure the server through a configuration file.'


## Configuring the server through an environment file

Batman wanted to configure the server through an environment file. Changing code continuously induced the risk of error.

## Environment Variables

 - `ROBYN_PORT`: Specifies the port on which the Robyn server will listen.
    - Default: `8080`
    - Example: `ROBYN_PORT=3000`
 - `ROBYN_HOST`: Specifies the host address for the Robyn server.
    - Default: `127.0.0.1`
    - Example: `ROBYN_HOST=0.0.0.0`
 - `ROBYN_BROWSER_OPEN`: Open the browser on successful start.
    - Default: `False`
    - Example: `ROBYN_BROWSER_OPEN=True`
 - `ROBYN_DEV_MODE`: Configures the dev mode
    - Default: `False`
    - Example: `ROBYN_DEV_MODE=True`
 - `ROBYN_MAX_PAYLOAD_SIZE`: Sets the maximum payload size for requests in bytes.
    - Default: `1000000` bytes
    - Example: `ROBYN_MAX_PAYLOAD_SIZE=1000000`

You can have a `robyn.env` file to load them automatically in your environment.

These environment variables are typically set in a `robyn.env` file located at the root of the project. The server parses this file at startup to configure itself accordingly.

For more details on the structure and usage of the `robyn.env` file, refer to the documentation snippet:

```bash {{title: 'Sample project directory'}}
--project/
  --robyn.env
  --index.py
  ...
```

Sample `robyn.env` file:

```bash {{ title: 'Sample Robyn.env' }}
ROBYN_PORT=8080
ROBYN_HOST=127.0.0.1
RANDOM_ENV=123
ROBYN_BROWSER_OPEN=True
ROBYN_DEV_MODE=True
ROBYN_MAX_PAYLOAD_SIZE=1000000
```

With the web application deployed and running smoothly, Batman had a powerful new tool at his disposal. The Robyn framework had provided him with the flexibility, scalability, and performance needed to create an effective crime-fighting application, giving him a technological edge in his ongoing battle to protect Gotham City.


## What's next?

Batman - Thanks, Robyn. Now tell me more.
Robyn - Let us learn about the Middlewares and events now!

- [Middlewares](/documentation/en/api_reference/middlewares)

